From Minecraft Parkour Wiki
isn't assigned a value because it has no importance. By convention, the 0th tick corresponds to the player's initial velocity before jumping.
corresponds to the initial jump motion. It is increased by 0.1 per level of Jump Boost
- Jump height is slightly higher in 1.9 due to the momentum threshold being reduced (old=1.249, new=1.252)
- Terminal velocity is -3.92 m/t
- When the player collides vertically with a block, vertical momentum is cancelled and only the acceleration is left.